The present invention relates to a door for a refrigerator having load reinforced comer brackets that support with improved thermal performance at least one door reinforcement member extending across the width of the door.
For several years the trend in domestic refrigerator cabinets has been to increase the size and in particular the width of the food compartments and doors in top or bottom mount refrigerators.
Typically, the refrigerator door is constructed from an outer door panel of sheet steel material having rearwardly extending side walls. The door has an inner liner wall of plastic material attached to the door panel. Foam insulation is injected in the space between the outer panel and the inner liner. The foam expands and cures to thermally insulate and rigidify the door.
In order to conserve costs, the amount of steel used in the manufacture of these doors is optimized. The practice is to use a relatively thin sheet of steel for the outer panel. Often this sheet is in the order of 0.017 inches thick. Consequently, in order for the refrigerator door to maintain it""s integrity and support articles or items stored on door mounted shelves, one common approach is to reinforce the door with cross braces located within the space of the door between the inner liner and the outer door panel. More typically, the metal cross braces extend adjacent the inner liner wall. The metal cross braces extend from the comers of the refrigerator outer panel in an X configuration across the width of the door to reinforce the refrigerator door. In some refrigerators, the braces are either attached directly to the outer door panel by being fastened to in-turned flanges that are parallel to and spaced from the outer door panel. In other refrigerators, cross brackets are attached to these in-turned flanges and extend across the door completing the base of a triangle with the door corner. The metal braces are attached to the cross bracket at the middle of the base of the triangle.
Another known approach to rigidify the door is to use a sheet of paper, aluminum foil or cardboard embedded adjacent the inner door liner in the insulation injected into the door cavity. This paper sheet is sufficiently large to cover the inside of the door and is taped to the door to prevent shifting. The sheet improves the rigidity of the door without significantly adding to the weight or cost of the door. Recently, metal sheets have been substituted for paper to improve rigidity. Even more recently, a rectangular shaped metal collar has been attached to the inner liner and a sheet of paper extends across the rectangular opening in the collar adjacent the inner door liner.
While the above described approaches in refrigerator door construction improve the rigidity of the door, these solutions are primarily directed to reinforcing the door outer skin and inner liner. To further strengthen the door outer skin, the comers of the door, formed when the skin is rolled back onto itself to provide a supporting peripheral flange for the door liner, have been welded to strengthen the comers. Alternatively, metal brackets have been inserted into the comers of the door to which vertically extending posts or hollow tubes extending along the vertical wall have been used to strengthen the comers.
The problem with most of the door reinforcement that extends across the width of the door to rigidify the door is that some portion of the reinforcement is attached to an inside flange of the outer door shell where the liner periphery is attached closely adjacent the refrigeration cavity and or, the reinforcement is in heat transfer relation with the inner door liner that faces the refrigeration cavity when the door is closed. As a result, the a portion of the door reinforcement to the refrigeration cavity provides a heat conducting transfer medium that fluctuates in temperature as the door is opened and closed. Furthermore, a heat transfer path from the inside of the refrigeration cavity through the door reinforcement and door is present.
Clearly there is a need for a refrigerator door reinforcement that rigidifies the door, supports the comers of the door and at the same time restricts heat transfer through the inner door liner to the reinforcement and out through the door.
It is an object of the present invention to provide a refrigerator door construction having door comer brackets and one or more door reinforcement members attached to the brackets and extending across the width of the door that rigidities the door and limits heat transfer through the door.
The present invention relates to a refrigerator appliance and, in particular, a door for a refrigerator appliance where the door includes reinforcing corner brackets that structurally complete the comers of the door. The corner brackets are located at the door corners adjacent vertical and horizontal side walls of the outer door skin. The brackets structurally support the horizontal and vertical side walls immediately adjacent the comer with a thicker, stronger material, such as, for example, metal or steel, so that loading normally transferred to the outer door skin through the horizontal side wall at this comer location is instead transferred directly to the brackets mounted in the door. In addition, the present invention connects at least one reinforcing member such as a sheet or rectangular collar, for example, or preferably reinforcing cross brace members to the corner brackets. To achieve this connection and restrict heat transfer through the door or adjacent the inner liner or in-turned flange of the outer door skin, the corner brackets have connecting tab portions that extend into the cavity of the door away from one of the side walls of the door and spaced from the other side wall of the door. The connecting tab portion is also spaced from the outer skin sheet and the inner door liner. As a result, the reinforcing member or members extend substantially across the width of the door spaced from the outer door skin wall and the inner door liner and are connected to the connecting bracket which is connected in heat transfer relation with side walls, horizontal or vertical, of the door. This reduces heat losses from the refrigerator cabinet conducted through the reinforcing member or members of the door.
In accordance with an aspect of the present invention there is provided a door for a refrigerator appliance comprising an outer door panel having an outer skin sheet with rearwardly extending peripheral vertical and horizontal side walls and four corners positioned between adjacent horizontal and vertical side walls. The door further comprises an inner door liner secured to the outer door panel spaced from the sheet to define a cavity between the inner liner and the sheet. The door comprises reinforcing corner brackets positioned within the cavity adjacent respective ones of the comers. The comer brackets each have a base wall extending substantially flush with, along and secured to at least one of the horizontal and vertical side walls to reinforce the corners. The base wall has a connecting tab member extending from the base wall and inwardly from the corresponding one of the horizontal and vertical side walls. The connecting tab member is spaced from the outer skin sheet and the inner door liner. The door further includes a pair of diagonally extending cross braces. Each cross brace has opposing end portions connected within the cavity to the connecting tab of diagonally opposed comer brackets and extending substantially across the door width within the cavity in spaced non-contacting thermal relationship from the outer skin sheet and the inner door liner to reinforce the door.
The horizontal side walls may have an open section adjacent the vertical side walls whereby the horizontal side wall ends at the open section. The brackets may each include a land section with an opening extending across the open section in the horizontal side wall for receiving a hinge pin in the opening of the land section.
The base wall of the bracket preferably extends along the horizontal side wall and the connecting tab member is spaced from the vertical side wall and extends into the cavity from the horizontal side wall. Alternatively, the base wall of the bracket extends along the vertical side wall and the connecting tab member is spaced from the horizontal side wall and extends into the cavity from the vertical side wall. Preferably, the base wall of the comer brackets is secured by toggle lock connection to a corresponding one of the horizontal and vertical side walls.
The outer door panel preferably has in-turned flanges extending from the horizontal and vertical side walls generally parallel to the outer skin sheet. The reinforcing comer brackets preferably each include a side flange that extends along an inside surface of the in-turned flanges of the horizontal and vertical side walls adjacent a respective corner. Preferably, portions of the side flange of the corner brackets extend beyond the in-turned flanges for connection to the inner door liner.
In an alternative embodiment, the reinforcing braces are replaced by a reinforcing metal sheet having connecting portions connected within the cavity to the connecting tabs of the corner brackets and extending substantially across the door width within the cavity in spaced non-contacting thermal relationship from the outer skin sheet and the inner door liner to reinforce the door. The reinforcing sheet may be continuous or form a rectangular frame or collar with a sheet of paper spanning the sheet.